I just finished John J. Lumpkin’s excellent novel Through Struggle, the Stars, and highly recommend it. In addition to being a very respectable first novel by an excitingly original author Through Struggle, which depicts a — to steal Rick Robinson’s term — plausible mid-future interstellar conflict, admirably tries to accurately depict realistic space combat. Set in 2139, the novel attempts to plausibly extrapolate a future global political and economic system incorporating extensive off-world colonization, and with the exception of “limited” wormholes (the opening must be physically transported to its ultimate destination; meaning a roughly ten light year travel limit and no causality violations) the space technology does not violate our understanding of what’s possible.

While the novel’s protagonist is engaging and the narrative interesting, Lumpkin’s worldbuilding is what I found most intriguing. In imaging humanity 130 years in the future Lumpkin reaches some interesting conclusions. Some I find plausible, others less so. Some scattered thoughts [no spoilers]:

Lumpkin has obviously thought a lot about the the shape of human society over a century into the future. The United States of 2139 is refreshingly multiethnic, with lots of Hispanic names in evidence. It’s also mentioned offhand that the average skin tone of Americans is a “light brown”; again, an encouraging acknowledgment of the US’ changing ethnic makeup. However, the humans the 22nd century seem to be very similar to today’s: aside from retina displays, little “posthuman” genetic augmentation, technological implants, or pharmaceutical alteration is seen. To be sure, social factors will probably play a greater role in determining the future prevalence of posthuman-type augumentation than technology, but their absence feels strange.

Through Struggle depicts a world where nation-states have extensively colonized nearby systems — China, Japan, the US, and UK, among others, are all shown to possess colony worlds home to millions of people (the US is 52 states strong; presumably two are off-Earth). The international order of Through Struggle is significantly more adversarial and unstable than today’s. Lumpkin cleverly suggests that off-Earth activity is destabilizing: individuals who mature in mono-ethnic colonies are more bigoted than those on Earth, and mercantilist trade between nations and their colony worlds has reduced international trade.

I’ve previously discussed why I find mid-future space colonization implausible: current humans don’t seem to meet the requirements of an expansionistic species, and living off-Earth will always be more expensive and less comfortable than remaining in the cradle. Lumpkin partially adresses these concerns by implying that colonization is more driven by a Scramble for Africa-style pressure to keep pace with competing states than rational expansion, but his depiction of colonizing “ranchers” lured off Earth by the prospect of free land seems antiquated at best. Population pressures sparked by extreme life extension could arguably justify off-Earth colonization — though I’m skeptical that humans will ever command the resources necessary to move a significant portion of humanity out of Earth’s gravity well — but Lumpkin never mentions life extension, aside from off-handed references to ‘sixty year’ careers.

In his imagined future, the United States is a distant third ranked power behind China and Japan, which at the novel’s opening are on the brink of war. China’s global leadership position is more than plausible — in fact, it’s difficult to imagine any ‘not-awful/nation states exist’ future where China’s massive population doesn’t guarantee it superpower status. But Japan as a future superpower crosses the line from plausible to extremelyunlikely, at least in my mind. Japan’s population is expected to fall to under fifty million by the 22nd century, and its strategic outlook will likely be dominated by attempting to counter growing Chinese regional hegemony — a future not conductive to attaining great power status. I understand that, for narrative purposes, Lumpkin requires the the novel’s American protagonists to not represent the world’s most powerful state. But assuming that the United States loses its position of global preeminence in the next century, India would be a much more realistic leadership choice in a bi- to multipolar world, alongside China.

I do find Lumpkin’s depiction of Iran as a future US ally credible. If China continues to grow economically and incorporates central Asia into its sphere of influence, a realist Iranian government could find closer ties with Washington an attractive counterbalance to Chinese influence, especially assuming (as Lumpkin seems to) that India remains a minor power.

In Lumpkin’s future, numerous nations field space combat fleets, including smaller states like Korea, Iran, various Latin American nations, and the UK. I find this very unlikely. Even assuming that technological progress, the advent of autonomous construction techniques, and off-planet economies of scale, interstellar spacecraft are extremely expensive. Today there’s only a single superpower capable of fielding a fleet of nuclear aircraft carriers, which are maybe an order of magnitude less complex than a starship. If the international order of a future starfaring humanity remains structured around competing nation states, I would expect only a few of the largest and richest countries to command the resources necessary to construct starships, if any elect to at all.

On the economic side, Through Struggle makes no mention of space elevators, even though constructing one would appear well within the technological and organizational capabilities of civilizations capable of constructing wormhole networks. I’m skeptical that the type of space economy that Lumpkin imagines is possible with out space elevators to ease transport out of Earth’s gravity well. This seems a missed opportunity for geopolitical drama as well: in a balkanized world nations without territory along the equator would have a much more difficult time constructing an elevator of their own, an enormous strategic handicap. (Most designs for space elevators rely on centrifugal force from Earth’s rotation to support the elevator, meaning they must be built near the equator).

Through Struggle is a war story. This raises some problems; while speculating about future space combat is an interesting thought experiment, there are reasons to suspect that open, large-scale wars in space are unlikely. Almost by definition, a future politically stable and rich enough to build starships means a world where humanity will continue to grow wealthier and more educated, and presumably be less inclined towards major wars. Starship construction also arguably implies post-scarcity, reducing the material payoffs from victory. If we accept the common ‘naval warfare as space warfare analog’ premise, then the fact that humanity has not fought a naval war in seventy years is also certainly suggestive.

Another barrier to open space warfare is the cost of space assets themselves. As previously mentioned, spaceships are very expensive, and likely always will be. Today the cost of major naval combatants has kept a global blue water navy the sole preserve of the United States since World War II — even the Soviets were unwilling to attempt to gain the US’ naval power projection capabilities, preferring to invest in asymmetrical sea denial assets like submarines and anti-ship missile systems. China appears to be following a similar path today.

Following this analogy, the first nation to field space combat forces would enjoy a massive advantage, perhaps one strong enough to steer potential rising adversaries towards “space-denial” asymmetric strategies rather than a “black-space” power projection force. Similarly, space combat assets could be so expensive that militaries are loath to risk them, and adversaries refrain from directly targeting opponents’ major assets out of fear of mutual losses or escalation.

That said, what would space combat look like? Fiction provides plenty of examples. Despite fielding directed energy weapons and immensely powerful engines, the warships of Star Trek and Star Wars inexplicably engage at extremely close range. The (comparatively) primitive warships of 2004’s Battlestar Galactica similarly close to a few kilometers before pounding away with artillery and defending themselves with close-in weapons systems similar to those modern navies use today (in the vacuum of space conventional artillery is a perfectly credible weapons scheme). However, while dramatic these depictions of space combat aren’t that realistic.

Lumpkin’s depiction of space conflict is obviously very carefully researched, and is impressive. Like Rick Robinson and Winchell Chung, Lumpkin discounts the possibility of stealth in space — a spacecraft will always be a hot target against a very cold background, with detection ranges in the millions of kilometers, at least. However, unlike Lumpkin I’m not convinced that stealthed weapons systems are impossible, at least under certain conditions. As some of the commenters at Robinson’s blog have speculated, it could be possible to soft-launch an missile actively cooled to the temperature of the cosmic background from a ship that wouldn’t accelerate until it was within the minimum kill range of the target’s defensive close-in weapons systems. Such a missile would be very hard to detect. However, I’m skeptical about the real world combat utility of stealthed kinetic missiles. To maintain a low signature, these weapons would have to maneuver by using their liquid helium cooling fluid. But this type of thruster would be capable of only low delta-v, making it very difficult for a low observable cold weapon to catch a maneuvering target at all, even if the target never knew it was there!

Here Lumpkin’s mix of lasers, nuclear and conventionally armed missiles and kinetic weapons is accurate. One use of stealthed remotely-fired weapons he doesn’t mention is nuclear-pumped x-ray lasers. One ship could eject several of these devices, which would then move laterally away from each other. Before firing they would be largely undetectable, negating the danger of counter-laser-lasers damaging your laser system, a frequent occurrence in the novel. Firing several at once from different angles would increase the chances of killing the enemy ship, and the firing could be timed to coincide with the impact of kinetic weapons, similar to the Russian air combat practice of firing two missiles with different targeting systems at a single target to increase the chance of a kill. These weapons would be a low-cost augment to Lumpkin’s ship-based laser systems and mass drivers.